The brains of those who are born blind make new connections in the absence of visual information, resulting in enhanced, compensatory abilities such as a heightened sense of hearing, smell and touch, as well as cognitive functions (such as memory and language) according to a new study led by Massachusetts Eye and Ear researchers. The report, published online today in PLOS One, describes for the first time the combined structural, functional and anatomical changes in the brain evident in those born with blindness that are not present in normally sighted people.
"Our results demonstrate that the structural and functional neuroplastic brain changes occurring as a result of early ocular blindness may be more widespread than initially thought," said lead author Corinna M. Bauer, Ph.D., a scientist at Schepens Eye Research Institute of Mass. Eye and Ear and an instructor of ophthalmology at Harvard Medical School. "We observed significant changes not only in the occipital cortex (where vision is processed), but also areas implicated in memory, language processing, and sensory motor functions."
The researchers used MRI multimodal brain imaging techniques (specifically, diffusion-based and resting state imaging) to reveal these changes in a group of 12 subjects with early blindness (those born with or who have acquired profound blindness prior to the age of three), and they compared the scans to a group of 16 normally sighted subjects (all subjects were of the same age range). On the scans of those with early blindness, the team observed structural and functional connectivity changes, including evidence of enhanced connections, sending information back and forth between areas of the brain that they did not observe in the normally sighted group.
These connections that appear to be unique in those with profound blindness suggest that the brain "rewires" itself in the absence of visual information to boost other senses. This is possible through the process of neuroplasticity, or the ability of our brains to naturally adapt to our experiences.
The researchers hope that increased understanding of these connections will lead to more effective rehabilitation efforts that will enable blind individuals to better compensate for the absence of visual information.
"Even in the case of being profoundly blind, the brain rewires itself in a manner to use the information at its disposal so that it can interact with the environment in a more effective manner," said senior author Lotfi Merabet, O.D., Ph.D., director of the Laboratory for Visual Neuroplasticity at the Schepens Eye Research Institute of Mass. Eye and Ear and an associate professor of ophthalmology at Harvard Medical School. "If the brain can rewire itself -- perhaps through training and enhancing the use of other modalities like hearing, and touch and language tasks such as braille reading -- there is tremendous potential for the brain to adapt."
FAQs
Summary: The brains of those who are born blind make new connections in the absence of visual information, resulting in enhanced, compensatory abilities such as a heightened sense of hearing, smell and touch, as well as cognitive functions (such as memory and language) according to a new study.
How do blind people's brains rewire to improve other senses? ›
These connections that appear to be unique in those with profound blindness suggest that the brain “rewires” itself in the absence of visual information to boost other senses. This is possible through the process of neuroplasticity, or the ability of our brains to naturally adapt to our experiences.
Are blind people's senses enhanced? ›
These connections, which are not present in normally-sighted individuals, cause an enhancement in non-visual abilities such as heightened sense of hearing, smell and touch — as well as cognitive functions such as memory and language.
How does the brain respond to blindness? ›
"After blindness occurs, the brain tries to compensate for the loss by ramping up its sensitivity to the missing visual signals," explains Denise Manahan-Vaughan, who led the study. When this fails to work, the other sensory modalities begin to adapt and increase their acuities.
What is brain plasticity in blind people? ›
The brain plasticity occurs in individuals who lost sight in the first years of life both from the functional point of view and in the recruited brain area extension. The cross-plasticity occurs in response to vision sensory deprivation in visually impaired individuals.
How do blind people sense other people? ›
The acoustic signals are always combined by blind and visually impaired people with the impressions of their sense of touch obtained by spatial probing with a stick. The interpretation of spoken words in a conversation is also better developed in the blind and visually impaired.
Can you train your other senses? ›
Fortunately, there's now a wealth of evidence that we can train our many senses, to improve not only how we use our bodies, but how we think and behave, as well as how we feel.
Which sense is strongest for blind people? ›
It is presumed that blind persons do not only hear better and have an intensified tactile sense but also have a stronger sense of smell. Better hearing ability was demonstrated by auditory evoked potentials.
What senses are heightened in blindness? ›
In fact, the MRIs showed evidence that a blind person's brain has more enhanced pathways than a person with full use of their vision. These results suggest the brain can “reroute itself” by creating new pathways. It also suggests that your other senses become enhanced to compensate for the missing one.
Can a blind person hear a heartbeat? ›
The analysis showed that the blind participants were superior at sensing their heartbeats than sighted participants. The blind group had an average accuracy of 0.78 while the sighted group had an accuracy of 0.63 on average, according to a scale where 1.0 represented a perfect score.
Blind people may hear better; the deaf can have a type of enhanced vision. These “super senses” are not just learned behavior — the brain actually remodels itself, giving more real estate to other senses when one is missing.
What happens to your senses when you go blind? ›
In blind people, the visual cortex gets a bit “bored” without visual input and starts to “rewire” itself, becoming more responsive to information from the other remaining senses. So blind people may have lost their vision, but this leaves a larger brain capacity for processing the information from other senses.
What are the strengths of blind people? ›
People who are blind or partially sighted are very adaptive, innovative, resourceful, and creative. I love how each of us on the National Youth Council are diverse with a unique view of the world.
What is the blind brain theory? ›
Given the central assumption of Blind Brain Hypothesis, that "information that finds its way to consciousness represents only a small fraction of the brain's overall information load," humans are likely likewise unable to account for the causal history of thoughts and behaviours.
Why is brain plasticity bad? ›
Plastic changes can also be harmful and cause symptoms and signs of disorders such as some forms of chronic pain (central neuropathic pain) and severe tinnitus.
Can you regain brain plasticity? ›
The brain's potential to adapt and regain cognitive skills is demonstrated by cognitive rehabilitation methods that use neuroplasticity, such as memory training, cognitive remediation, and attention enhancement approaches.
What is a sensory substitution for the blind? ›
The best known sensory substitution method is the tactile Braille alphabet. This is a written language which was invented by the Frenchman Louis Braille in 1824, but it was not universally accepted until after his death many years later.
Do brains of blind people adapt to sharpen sense of hearing study shows? ›
Brains of blind people adapt to sharpen sense of hearing, study shows. People who are visually impaired rely on other senses to interpret their surroundings. A pair of studies from the University of Washington shows how the brains of blind people adapt to process information.
How does blindness affect the sensory system? ›
In fact, the MRIs showed evidence that a blind person's brain has more enhanced pathways than a person with full use of their vision. These results suggest the brain can “reroute itself” by creating new pathways. It also suggests that your other senses become enhanced to compensate for the missing one.
